Diabetes mellitus is one of the leading chronic diseases of childhood and adolescence, and incidence is increasing worldwide. The spatial or geographic variation in incidence of diabetes is one of the largest observed for any non-communicable disease. Very little is known about geographic variation within the United States. While in the past pediatric diabetes has been thought of largely as Type 1, pediatric Type 2 diabetes (non-autoimmune and non-insulin-dependent) has recently emerged. The SEARCH for Diabetes in Youth Study was initiated in 2000 to estimate population prevalence and incidence of diabetes in ethnically- diverse youth under the age of 20 years in the United States by age, gender, race/ethnicity, and diabetes type. This ancillary study to SEARCH aims to (1) describe and map the spatial distribution of incident pediatric diabetes, including Type 1 and Type 2 in the ethnically and geographically diverse SEARCH populations from South Carolina, Ohio, Colorado, and Washington;(2) evaluate the association of incidence of Type 1 and Type 2 diabetes with geographic and neighborhood characteristics (location, urbanization, population density, socio-economic characteristics) in a series of statistical, ecologic analyses;(3) to explore the extent to which aggregate geographical and neighborhood characteristics influence risk of Type 1or Type 2, once established individual-level risk factors are taken into account, in a multi-level analysis combining data from SEARCH with the SEARCH Case Control study. This effort may provide novel leads for subsequent etiologic studies of pediatric diabetes and will assist health care planners in identifying geographic areas in particular need of health services resources.